The subject matter disclosed herein relates generally to turbine systems and, more particularly, to methods and systems for controlling thermal differential in turbine systems.
At least some known turbine systems include a compressor that compresses air channeled downstream through the turbine system. During startup operations and/or shutdown of at least some known turbine systems, at least some portions of such compressors and/or rotors may be subjected to high temperatures, thermal gradients, high stresses, and/or vibrations. For example at least some known compressors include a plurality of stages that increasingly compress and, consequently, increase a temperature of air channeled therethrough. Such differences in airflow temperature may result in thermal gradients developing within the compressor. Moreover, at least some surfaces are exposed to the flow path more than other portions of the compressor. As a result, other thermal gradients may develop within compressor. Such thermal gradients and/or thermal stresses may cause uneven expansion, bending, and/or other stresses within the compressor that, at times, could lead to undesired slipping and/or rubbing of compressor components.
To improve an efficiency and/or a power output of at least some turbine systems, a compressor discharge temperature, a firing temperature, and/or a core flow rate may be increased. However, increasing any of the aforementioned operational characteristics could increase the likelihood of thermal gradients and/or thermal stresses being developed within the compressor and/or the rotor.